This invention relates to the remote control of medical devices in a subject's body, and in particular to a user interface for operating a remotely controllable medical device which employs a “virtual device” interface.
Advances in technology have resulted in systems that allow a physician or other medical professional to remotely control the orientation of the distal end of a medical device. It is now fairly routine to steer the distal end of a medical device inside a subject's body by mechanically manipulating controls on the proximal end of the medical device. Recently magnetic navigation systems have been developed that allow a physician to orient the distal end of a medical device using the field of an external source magnet. Other systems have been developed for the automated remote orientation of the distal end of a medical device, for example by operating magnetostrictive or electrostrictive elements incorporated into the medical device. However the medical device is controlled, it can still be difficult for a physician to visualize the procedure site (which is out of view inside the patient's body), to selected the desired direction in which to orient the distal end of the medical device and communicate the selected direction to the system in order to orient the distal end of the medical device in the selected direction.
As stated above, magnetic navigation systems have been developed which apply a controlled magnetic field to an operating region in a subject, to orient a magnetically responsive element on a medical device in the operating region. Examples of such systems include Ritter et al., U.S. Pat. No. 6,241,671, issued Jun. 5, 2001, for Open Field System For Magnetic Surgery (incorporated herein by reference). Magnetic navigation systems permit faster and easier navigation, and allow the devices to be made thinner and more flexible than conventional mechanically navigated devices which must contain pull wires and other components for steering the device. Because of the advances made in magnetic surgery systems and magnetically responsive medical devices, the determination of the appropriate field direction, and instructing the magnetic surgery system to apply the determined magnetic field are probably the most difficult tasks remaining in magnetically assisted medical procedures. Significant efforts have been made to help the user to visualize the procedure, and improve the user's ability to control the magnetic surgery system during the procedure. There is often a lag between the direction of the applied field, and the actual direction of the distal end of the medical device. In some current systems, the user specifies a field direction, and mentally must take into account the lag between the applied field and the actual device direction.